The present invention relates to an electrical connector for use in electric or electronic appliances, and more particularly to an electrical connector with signal contacts and ground contacts improved in arrangement and construction for use in high speed transmission.
There is disclosed in Japanese Patent Application Opened No. 2000-507,740 an electrical connector assembly including an insulating housing, a plurality of terminal modules incorporated therein and conductive shields therebetween. Each of the terminal modules includes a plurality of contacts each of which consists of a fitting contact portion, a conductor connection portion and an intermediate portion therebetween, the intermediate portion being completely or partly enclosed and held in an insulating web. Each of the modules has a conductive shield attached thereto.
With this connector assembly, each shield at least includes a first elastic arm adapted to be brought into electrical contact with one contact selected from contacts in the terminal module to which the shield is secured, and a second elastic arm outwardly extending from the adjacent terminal module and adapted to be brought into electrical contact with one contact selected from contacts in the adjacent terminal module.
For the purpose of providing an electrical connector with ground contacts to be easily manufactured, disclosed in Japanese Patent Application Opened No. 2002-50,436 is a connector having a plurality of signal contacts arranged in a predetermined plane and ground contacts arranged between the signal contacts, these contacts being held in an insulator. The insulator is provided on its specific surface with a ground plate secured thereto and is formed with windows through which parts of the ground contacts and parts of the signalcontacts adjacent thereto are exposed, the ground plate having contact portions adapted to contact the ground contacts through the windows.
These known connectors disclosed in the two patent literatures are intended to adapt to the high speed transmission and have an object to reduce the cross talk between signals passing through a plurality of signal contacts.
Moreover, a prior art proposal has attempted to reduce the cross talk by arranging contacts in a particular arrangement as shown in FIG. 5. In more detail, signal contacts (+S1, +S2, +S3 . . . ), phase inversion signal contacts (−S1, −S2, −S3 . . . ), and ground contacts (G) are arranged in a manner that ground contacts (G) surround a pair of contacts +S1 and −S1, a pair of contacts +S2 and −S2, a pair of contacts +S3 and −S3, . . . As can be seen from FIG. 5, it may be recognized in this arrangement that the ground contacts are arranged between pairs of contacts, each pair consisting of a signal contact and a phase inversion signal contact.
The connectors disclosed in the above patent literatures and the prior art proposal are beneficial to some extent for obtaining high shielding effect and high speed transmission.
With the case of arranging ground contacts between pairs of signal contact and phase inversion signal contact, if a pitch between the contacts is very narrow, clearances between the ground contacts would unavoidably become large. In the connectors disclosed in the Japanese Patent Application Opened Nos. 2000-507,740 and 2002-50,436, it is also unavoidable to enlarge clearances between the shielded signal contacts to some extent, so that sufficient shielding effect could not be obtained. As a result, the transmission speed would be limited to the order of several hundreds Mbps, which would not fully comply with imposed requirement of even higher speed transmission in future. Whereas efforts to date have been beneficial, technical problems remain to be solved.
With the connectors disclosed in the patent literatures described above, the number of parts inevitably increases so that the cost would go up concerning their management and fabrication.